It has long been known in the disposable absorbent bandage art that it is extremely desirable to construct absorptive devises such as disposable diapers, catamenials, sanitary napkins, incontinent articles, and the like, presenting a dry surface feel to the user to improve wearing comfort and to minimize the development of undesirable skin conditions due to prolonged exposure to moisture absorbed within the bandage.
One viable prior art solution to the aforementioned problem is disclosed in commonly assigned U.S. Pat. No. 4,342,314 issued Radel et al. on Aug. 3, 1982 and hereby incorporated herein by reference. Radel et al. discloses an absorbent bandage with a wearer-contacting topsheet comprising a resilient macroscopically expanded, three-dimensional, plastic web exhibiting a combination of fiber-like and plastic properties. In a preferred embodiment, the macroscopically expanded, three-dimensional, plastic web topsheet disclosed in Radel et al. exhibits a fine scale three-dimensional microstructure comprising a regulated continuum of capillary networks originating in and extending from one surface of the web and terminating in the form of apertures in the opposite surface thereof to promote rapid fluid transport. The web's fiber-like appearance is comprised of a continuum of fiber-like elements, the opposed ends of each of the fiber-like elements are interconnected to at least one other of the fiber-like elements.
A typical capillary network in the Radel et al. structure comprises an uppermost capillary opening or aperture formed by a multiplicity of fiber-elements interconnected to one another in the uppermost plane of the web. Each of the fiber-like elements exhibits a substantially uniform U-shaped cross-section along its length. The cross-section of the fiber-like element comprises a base portion located in the wearer-contacting plane and a sidewall portion joined to each edge of the base portion, the sidewall portions extend generally in the direction of the absorbent pad-contacting surface of the web. The sidewall portions which intersect one another are joined to one another intermediate the wearer contacting surface and the absorbent pad contacting surface of the web, thereby forming a capillary network interconnecting the opposed surfaces of the web.
A topsheet of the type generally disclosed by Radel et al. is highly effective in promoting rapid fluid transfer from the first wearer-contacting surface to the second absorbent pad-contacting surface of the topsheet. Accordingly, topsheets of this type have enjoyed widespread commercial success on catamenial pads due to their clean and dry appearance in use when contrasted to conventional nonwoven fibrous topsheets. While the Radel et al. topsheet is highly effective in promoting rapid transfer of bodily fluids from the first wearer-contacting surface to the second absorbent pad-contacting surface, bodily fluids, e.g., menses, may hang up in the apertures along the pad contacting surface unless the apertures are in fluid transporting contact with an underlying layer, e.g., the absorbent core. Typically, in order to ensure fluid transporting contact between the apertures in the pad-contacting surface and the underlying layers, an adhesive has been used. However, adhesives have a tendency to clog the apertures if applied too heavily. If the apertures become clogged, fluid is not permitted to drain through the topsheet thereby exposing the skin to moisture. In addition, bonding layers together with an adhesive to ensure fluid transporting contact throughout can produce a stiff structure which is uncomfortable. Furthermore, adhesives may not provide sufficient contact between the topsheet and the underlying layers if applied too sparingly or may delaminate and be rendered useless when wetted with body exudate.